The present invention relates to a mold structure to be used for molding a housing such as a connector housing, a molding method, and the housing molded.
The connector housing has a locking lance for locking a terminal in a terminal containing room, and is molded of resin by injection molding. A method of molding this connector housing is disclosed in Patent Document 1.
In this method, a core member for molding the locking lance is provided in one of a pair of molds which move relative to each other in a mold clamping direction. The core member includes a first core, and a second core which is provided in the first core and can move back and forth relative to the first core. In a state where the first core and the second core are aligned in parallel, a groove part for molding the locking lance is formed. The first core and the second core are arranged in parallel in a lateral direction of the locking lance.
In this molding method, resin material is filled in a clamped state of a pair of the molds thereby to mold the locking lance having flexibility in the aforesaid groove part, and when the molds are opened after solidification of the resin material, the second core is moved in a mold extracting direction. With this movement, the locking lance is flexed to be removed from the groove part, and an entirety of the connector housing is separated from the mold so that the connector housing is molded.
In the above described method, the locking lance is not forcibly extracted when it is removed, and therefore, the locking lance will not be broken.
[Patent Document 1] Japanese Patent Publication No. 2006-196214 A
In the molds to be used in the above described method, the core is divided into the first core and the second core which are arranged in parallel in the lateral direction of the locking lance. For this reason, in case where the locking lance having a small width is molded, the first core and the second core become further smaller, and rigidity of the core cannot be secured.
Moreover, on occasion of molding the locking lance, a groove where the second core moves in the mold extracting direction is formed in the lateral direction of the locking lance. Because this groove is formed, a locking area for locking the locking lance to a terminal becomes smaller. For this reason, there is a problem that terminal holding force of the locking lance cannot be sufficiently secured.